Mitsubishi Electric Mr.Slim PLA-RP100AA2 Service Manual page 23

Phenomena
(2)LED2 on indoor controller board
is blinking.
(3)Upward/downward vane
performance failure
(4)Receiver for wireless remote
controller
(5)Defective operation of fan
(The fan doesn't turn.)
To be continued to the next page.
Cause
• When LED1 on indoor controller board is also blinking.
Connection failure of indoor/outdoor unit connecting
wire
• When LED1 is lit.
1 Mis-wiring of remote controller wires
Under twin triple indoor unit system, 2 or more indoor
units are wired together.
2 Refrigerant address for outdoor unit is wrong or not
set.
Under grouping control system, there are some units
whose refrigerant address is 0.
3 Short-cut of remote controller wires
4 Defective remote controller
1 The vane is not downward during defrosting and
heat preparation and when the thermostat is OFF in
HEAT mode. (Working of COOL protection function)
2 Vane motor does not rotate.
• Defective vane motor
• Breaking of wire or connection failure of connector
• Up/down vane setting is "No vanes".
3 Upward/downward vane does not work.
• The vane is set to fixed position.
1 Weak batteries of wireless remote controller.
2 Contact failure of connector (CNB) on wireless
remote controller board.
(Insert failure)
3 Contact failure of connector (CN90) on indoor con-
troller board.(Insert failure)
4 Contact failure of connector between wireless
remote controller board and indoor controller board.
1 Defective fan motor.
(Fan motor's winding is short or open.)
2 Defective fan motor.
(Fan motor position sensor signal is not output.)
3 Defective indoor power board.
(fan-control circuit).
4 Defective indoor controller board.
23
Note: Refer to the manual of outdoor unit for the detail of remote
controller.
Check indoor/outdoor unit connecting wire
for connection failure.
1 Check the connection of remote con-
troller wires in case of twin triple indoor
unit system. When 2 or more indoor units
are wired in one refrigerant system,
connect remote controller wires to one of
those units.
2 Check the setting of refrigerant address
in case of grouping control system.
If there are some units whose refrigerant
addresses are 0 in one group, set one of
the units to 0 using SW1 (3-6) on outdoor
controller circuit board.
34 Remove remote controller wires and
check LED2 on indoor controller board.
• When LED2 is blinking, check the
short-cut of remote controller wires.
• When LED2 is lit, connect remote
controller wires again and:
if LED2 is blinking, remote controller
is defective; if LED2 is lit, connection
failure of remote controller terminal
block etc. has returned to normal.
1 Normal operation (The vane is set to hor-
izontal regardless of remote control.)
2 Check 2 (left).
• Check the vane motor. (Refer to "How
to check the parts".)
• Check for breaking of wire or connec-
tion failure of connector.
• Check "Up/down vane setting". (Unit
function selection by remote controller).
3 Normal operation (Each connector on
vane motor side is disconnected.)
1 Replace batteries of wireless remote con-
troller.
2~4
Check contact failure of each connector.
If no problems are found of connector,
replace indoor controller board.
When the same trouble occurs even if
indoor controller board is replaced,
replace wireless remote controller
board.
1 Check the resistance of fan motor's wind-
ing.
Refer to 9-6.
2 Turn around the fan motor more than one
revolution slowly, and check the voltage
of connector CN3.
(CN3:Refer to 9-7-1.)
Between pin1 and 5 or 2 and 5 or 3
and 5:
•0V DC
(The output voltage changes.)
Normal
•0V DC or 5V DC
(The output voltage doesn't change.)
NG
Replace the fan motor.
3 When the motor is normal
(Check 1 and 2),
replace the indoor power board.
4 When 3 is OK, replace the indoor con-
troller board.
Countermeasure
5V DC 0V DC